Vacuum pump



FIG. 1 is a perspective view of a vacuum pump showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken line showing of the vacuum pump is for the purpose of illustrating portions of the article and forms no part of the claimed design. 

CLAIM The ornamental design for a vacuum pump, as shown and described. 